Various arrangements are suggested in the prior art for automatically threading flexible web material from a supply reel to a take-up reel. The functions which the various threading mechanisms must perform are dependent, to a great extent, on the particular web transport mechanism with which the particular automatic threading mechanism must cooperate. Automatic threading mechanisms have been shown to be quite useful in connection with magnetic tape transport devices which move the tape media past a stationary magnetic transducer for the reading of previously stored information or for the storage of new information. For a number of well-known reasons, it is desirable to keep the segment of the tape that is being read or written on by the magnetic transducer as close as possible to the flux gap of the transducer and, also, to move the tape relative to the transducer at a substantially constant speed during reading and writing. Constraints such as these, plus others, result in the tape path between the supply reel and the take-up reel of a magnetic tape transport being somewhat complex and not linear. As tape paths have become more complex and magnetic tape thinner, and hence, more flexible, the prior art automatic threading arrangements, such as the pneumatic guiding of the end of the tape or providing a leader on the take-up reel which is automatically coupled to the end of the tape on the supply reel, have all suffered from one or more disadvantages.